Bolt lock



H. A. CARLSON BOLT LOCK June 10, 1952 Filed Jan. 28, 1946 FIG.|.

FIG.2.

Patented June 10, 1952 BOLT LOCK Harold A. Carlson, University City,Mo., assignor to Carter Carburetor Corporation,

St. Louis,

Mo., a corporation of Delaware Application January 28, 1946, Serial N 0.643,930

1 Claim. 1

This invention relates to so-called anti-rattler devices, particularly,of the type intended to prevent unauthorized rotation of threadedlyattached members with the resultant changing of the relative positionsor loosening thereof.

An example of the use of such devices occurs in automotive carburetorsin which the idle adjusting screw is carried by the throttle operatingarm. The screw engages a stop for limitin the closing movement of thethrottle valve and, consequently, the idling position thereof. Sincethis position is very critical, it is important that the position of theidle adjusting screw in the throttle arm remain fixed after it isproperly adjusted. A coiled spring has been symmetrically compressedbetween the throttle arm and screw head for accomplishing this purpose.However, because of the vibration of the engine and carburetor, thisspring has not been wholly satisfactory with the result that the screw,after use for a short time, is frequently found to have rotated and theidling adjustment of the throttle thereby affected.

The main object of the present invention is to provid improved means forresisting unauthorized relative rotation of threaded parts, such as theidle adjusting screw and throttle arm as above described.

A more detailed object is to provide novel means for causing the threadsof a screw, such as the throttle adjusting screw, to bind in the holdingmember.

These objects and other more detailed objects hereafter appearing areattained substantially by the device illustrated in the accompanyingdrawing in which:

Fig. 1 is a side view of an automotive carburetor with an idle adjustingscrew having the invention applied thereto.

Fig. 2 is an enlarged section illustrating a part of the throttle armand adjusting screw.

Fig. 3 is a view similar to Fig. 2, butillustrating a modification.

The carburetor illustrated in Fig. 1 is of the downdraft type having achoke valve (not shown) in the upper part mounted on a shaft 5 which hasan arm 6 rigid with one projecting end thereof. In the lower end of thecarburetor ther is the usual throttle valve (not shown) mounted on ashaft 1 on one projecting end of which there is rigidly attachedthrottle operating lever 8. This lever has a hole 9 for attachment oflinkage extending to the drivers compartment. A stub shaft Ill adjacentthe throttle shaft rotatably mounts a dog or cam II which has anapertured arm I2 receiving a link 13 connecting the dog to choke arm 6for operation therewith.

Idle adjusting screw I5 is threadedly mounted in one portion of throttlearm 8 so as to engage stub shaft ID or cam I l according to whether thechoke valve is wide open or in its closed position,

2 to limit the closing movement of the throttle valve to the normal orfast idle position. A coiled spring I6 is compressed between the head ofscrew [5 and the opposing surface of throttle arm 8. As best shown inFig. 2, this surface of the throttle arm is provided with anon-symmetrical countersink l'! about its threaded opening for screw 15. Thus the portion of the spring which engages the arm is caused tobear against the arm in a resultant direction at an angle to the axis ofthe screw and, specifically, to the axes of the threadedly attachedportions of the screw and throttle arm. The spring thus biases the screwat an angle to cause binding in the threads and, thereby, resistunauthorized rotation thereof.

In the modification shown in Fig. 3, the portion I9 of the adjustingscrew 15a immediately adjacent the head thereof is offset or eccentricrelative to the aXis of the screw. Thus the portion of spring it whichengages the screw head is similarly off-set so as to bear against thescrew head at an angle to the screw axis. As in the previous form, thiscauses the spring to bias the screw at an angle which results in bindingin the screw threads.

Other means may be provided for producing the non-parallel or biasaction of the anti-rattler spring. The invention may be modified invarious respects as will occur to those skilled in the art and theexclusive use of all modifications as come within the scope of theappended claims is contemplated.

I claim:

In a device of the class described, a tapped member, a bolt threadedlyreceived therein, a restricted portion of said tapped member beingcountersunk about but eccentric to the tapped opening therein, and acoiled sprin compressed between said tapped member and the bolt head,said eccentric countersink serving to bias the spring for betterresisting turning of the bolt due to vibration.

HAROLD A. CARLSON.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Great Britain 1913

